What is on my plants?
I cannot see too much from the picture but from your description my thought is that your plant has spittlebugs. These can easily be managed by hosing them off the plant with a strong stream of water. They do little damage to most plants. Here is a link you may like to read: http://insect.pnwhandbooks.org/hort/landscape/common/landscape-pests-spittlebug-and-froghopper